Lesson 7-9 Flashcards
The size of most bacteria ranges from
0.2 μm (micrometer) to 2.0 μm
in diameter and from 2.0 μm to 8.0 μm.
usually round but can either be oval,
elongated, spherical or elliptical shape
Cocci
: represented by single, discrete round cell.
Monococcus
divides but the cells remain
attached to each other.
Diplococcus
c. : here the cells divide repeatedly in one plane to form chain
of cells.
Streptococcus
: this consists of four round cells, which divide in two planes at
right angles to one another and remain in group of four.
e.
Tetracoccus
: here the cells divided into three planes forming a
Staphylococcus
structured like bunches of grapes giving and irregular configuration.
these cells divide in three planes but they form a cube like
configuration consisting of eight or sixteen cells but they have a regular
shape.
Sarcina
these are rod shaped or cylindrical bacteria which either remain singly or
in pairs.
Bacilli
appear in pairs after cell division
Diplobacilli
occurs in chain after cell division
Streptobacilli
: oval shaped similar to cocci
Coccobacilli
: curved, comma shaped bacteria and represented by a single genus.
Vibro
: spiral or spring like with multiple curvature and terminal flagella with
fairly rigid bodies.
Spirilla
: helical and flexible which move by means of axial filaments
resembling flagella but contained within an external sheath
Spirochete
are viscous substances that surrounds the cell
composed of polysaccharide, polypeptide or both.
Glycocalyx
Glycocalyx is composed of what?
Polysaccharide or polypeptides or both
Function of glycocalyx
-enables bacteria
to survive by attaching to surfaces
-bacterial source of energy
when supply is low
-protection to hosts cell by attaching to surface hence
preventing the movements of nutrients out of cell during dehydration
attaches to
the surface of the teeth and cause dental carries,
Streptococcus mutants
Two form of glycocalyx
Capsule form
Slime layer form
the substance is organized, is firmly attached to
the cell wall, and clinically contributes to the virulence (ability to cause disease) of
bacteria due to its capacity to evade phagocytosis by hosts cells
Capsule form
he substance in unorganized and is loosely attached to the cell wall
Slime layer form
are long filamentous appendages
that propel bacteria
Flagella
Three basic parts of flagella
Filament
Hook
Basal body
long outermost part that
contains flagellin arranged in helix,
Filament
where filament is attached to, and (3)
hook
anchors the flagellum to the cell wall and plasma membrane.
basal body
The
flagella move by rotating from the basal body either in ?
clockwise or
counterclockwise direction
bacterium moves in one
direction
run or swim
: periodic abrupt or random interruptions to run or swim
tumbles
: rapid wavelike movement
swarm
also called endoflagella present in Spirochetes like Borrelia
burgdorferi that causes Lyme disease
Axial filament
: is a type of a protein called pilin. It is a numerous hair like appendages
that surrounds the bacterium and helps to attach to hosts surfaces.
Fimbriae
: is another type of the protein pilin but is only presented in one or two per
bacterium. It also helps bacterial cell to prepare DNA transfer from one cell to
another
Pili
s a semi rigid structure protects the interior of the cell
from the outside environment.
The bacteria cell wall
Function of cell wall
-prevent ruptured of the cell
-maintain shape of the cell
-anchors flagella
-contribute to the virulence of the bacteria
-site of action of some antibiotics
-the chemical composition
of cell is used to differentiate types of bacteria.
The bacterial cell wall is primarily composed of network of
what?
It also called murein
peptidoglycan
have multiple layers of peptidoglycan in its cell wall for a thick
rigid structure
Gram positive bacteria
provide the antigenic capacity of
the bacteria making it possible to identify it upon laboratory tests.
Teichoic acids
has a thin layer of peptidoglycan
making it very susceptible to mechanical breakage or environmental degradation
Gram negative bacteria
Gram negative bacteria cell wall (outer portion) is composed of ?
lipopolysaccharide (LPS, also called
endotoxin), lipoproteins
phospholipids.
provides
antigenic capacity of the bacteria,
and
(2) causes physiological effects when
present in the bloodstream (toxicity, fever, sepsis, shock, or death).
Lipopolysaccharide or endotoxin
prevents reaction to Gram stains
Mycolic acids
Bacteria that composed of higher Mycolic acids can be stain with what?
Carbolfuchsin
lipopolysaccharide, lipoproteins and phospholipids. Functions
evades
phagocytosis and cell lysis,
(2) barrier to antibiotics and other enzymes, and (3)
passage of molecules thru porin channels.
lipopolysaccharide, lipoproteins and phospholipids. Functions
evades
phagocytosis and cell lysis,
(2) barrier to antibiotics and other enzymes, and (3)
passage of molecules thru porin channels.
resist removal with acid alcohol thus called
acid-fast bacteria.
having no cell wall or with very little wall material.
Atypical cell walls
Some chemicals like this can cause damage, or interfere with the
synthesis of cell walls by cell lysis.
lysozyme
Function of plasma membrane
entry/exit of substances in cell by selective permeability,
(2)
protect and lubricate the cell,
(3) cell-to-cell interactions
(4) breakdown of
nutrients and energy production
The movement of materials/substances across the membrane
Passive process
Active process
movement of molecules from high concentration to low concentration
Simple diffusion
same with simple diffusion but substances are transported
across the membrane via transporter
Facilitated diffusion
: movement of a solvent
molecule (water) from high concentration to low concentration via a selectively
permeable membrane
Osmosis
: the cell
uses energy to transport a substance from lower to higher concentration without
altering the substance,
Active transport
: a special type of active that
alters the substance being transported across a membrane.
group translocation
Cytoplasm is composed mainly of what?
Water
Proteins
Carbohydrates or lipids
Located in the cytoplasm of a bacterial cell contains double-stranded DNA each for the bacterial chromosome and plasmid
Nucleiod
Contains the genetic information of the cell
Bacteria chromosomes
Carry gene associated to antibiotics resistance, toxin production or enzyme synthesis.
Also important in gene manipulation of bacteria
Plasmid
Ribosomes in bacteria are called what?
70S ribosomes
used in ATP synthesis
metachromatic granules
Are iron oxides that acts like magnet to move until attachment site
magnetosomes
are released when bacterial cell is degraded.
It is capable of resistance to harsh chemicals, extreme environment condition and radiation
Endospores
resting cell formed internal the cell membrane when a bacterial cell goes into vegetative state or active cell that undergo metabolism
Sporulation
An endospores can remain dormant for a thousand years and can return to vegetative state by what? It is when endospores coat is triggered either by physical or chemical damage
Germination
harness the suns light to make food and generate energy without using oxygen.
Cyanobacteria
Sum of all chemical reaction within a living organism
Metabolism
an enzyme-regulated chemical
process that releases energy whereby complex organic compounds are breakdown
into simpler ones.
Catabolism
Catabolism mainly use what to break chemical bonds and produce more energy that they consume
Water
is an enzyme-regulated chemical process that
requires energy to build complex organic molecules from simpler ones. This reaction
mainly releases water (dehydration synthesis reaction), and consume more energy
that they produce (endergonic).
Anabolism
provide the building blocks for anabolic reactions and also
supply the energy needed for it in the form of adenosine triphosphate (ATP).
Catabolic reaction
The
formation or breakdown of chemical bonds is made possible by collision of atoms,
ions or molecules that are continuously moving and colliding with one another
Collision theory
The energy required for a chemical reaction
Activation energy
Factors that influence enzymatic activity
Temperature
pH
substrate
inhibitors
[compete with normal substrate for the active site]
competitive
[interact with another part of the enzyme].
non-competitive inhibitor
The process
by which non-competitive inhibitors carry out its function wherein inhibitors bind to parts of the enzyme other than
substrate binding site.
allosteric or
feedback inhibition
are a type of RNA that serving as catalyst acting specifically on
strands of RNA during protein synthesis.
Ribozymes
is the removal of electron from an atom or molecule in a reaction
that produces energy.
Oxidation
is gaining one or more electron.
Reduction
These
two reactions are always coupled, each time a molecule is oxidized
another is simultaneously reduced. Also used by cells in catabolism to extract energy from nutrient molecules
Redox reaction
ATP is generated when a high energy P
is directly transferred from phosphorylated compound to ADP
Substrate-level phosphorylation
. : electrons are transferred from organic
compound to a series of electron carriers in a system called electron
transport chain.
Oxidative phosphorylation
: occurs only in photosynthetic cells which contain
chlorophyll (light energy trapping pigments) that can be converted into
ATP in a process involving electron transport chain system.
Photophosphorylation
Three mechanism of phosphorylation
Substrate-level phosphorylation
Oxidative phosphorylation
Photophosphorylation
is the most common carbohydrate energy source used by cells.
Glucose
is the primary source of cellular energy in most
microorganisms.
Oxidation of carbohydrate
Two processes of Energy production from glucose
cellular
respiration
fermentation,
(both process starts with glycolysis)
an ATP-generating process wherein the final electron acceptor
is an inorganic molecule.
Cellular respiration
generate energy from sugars and other organic molecules such as
amino acids, organic acids, purines and pyrimidines by not requiring oxygen, Krebs cycle or electron transport chain system.
Fermentation
End product is ethanol
Alcohol fermentation
End product is lactic acid
Lactic acid fermentation
are broken down by extracellular enzymes called lipases before it undergoes
oxidation in Kreb’s cycle.
fatty acids and glycerol in lipids
The
chemical energy produced will then convert carbon dioxide in atmosphere to sugars
in a process called ?.
carbon fixation
is a life mechanism on earth to
recycle carbon dioxide excreted by other organisms (ex: human) to be used by
plants and other microorganisms.
Carbon fixation
: uses light energy to generate energy
(photophosphorylation)
Light-dependent (light) reactions
: breakdown of carbon dioxide into
sugar using energy generated in the first stage (Calvin-Benson cycle)
Light-independent (dark) reactions
Metabolic pathways that uses the energy generated by processes presented
above
- Polysaccharide biosynthesis
- Lipid biosynthesis
- Amino acid and protein biosynthesis
- Purine and pyrimidine biosynthesis
Cell division begins with what?
DNA replication
segregation of nucleiods
a Z-ring
composed
mainly
of what?
which is assembled in the
middle of the cell.
FtsZ polymers
recruits additional proteins
that serve for septum formation
and subsequent separation of the daughter cells
z-ring
is the time required for a bacterium to give rise to two
daughter cells under optimum conditions.
Generation time
Microbial concentration can be measured in terms what?
Cell concentration
Biomass concentration
the number of viable cells per unit volume of culture
Cell concentration
(dry weight of cells per unit volume of culture).
biomass concentration
denotes the total number of bacteria in the sample, irrespective
of whether they are living or dead
Total count
: indicates the number of living or viable bacteria.
Viable count
series of sequential dilutions used to reduce a dense
culture of cells to a more usable concentration
Dilution method
(number of
colonies that grow after a suitable incubation time).
plating method
is a method utilized for industrial and research purpose that
is achieved by using a special device for replenishing nutrients and removing
bacterial population continuously so that bacteria growth is not inhibited due to lack
of nutrients or due to accumulation of toxic bacterial metabolites.
Continuous culture
Minimum and maximum temperature of most bacteria
30 degree Celsius
Is when a species grow best
Optimum growth
pH level that bacteria most grow
6.5-7.5
when solution outside the cell has higher concentration of solutes than
inside the cell, water is diffused outside of cell and the cell shrinks.
Hypertonic environment
: when solution outside the cell has lower concentration of
solutes than inside the cell, water is diffused inside of cell and the cell
swells.
Hypotonic
: when concentrations in two solutions are same, so cell
will neither swells nor shrinks.
Isotonic
Important for all organic compounds that make up a living cell consist half the dry weight of a typical bacterial cell.
.
Carbon
helps form the amino group in amino acids
Nitrogen
used to synthesize sulfur-containing amino acids and vitamins
Sulphur
: important in synthesis of ATP, nucleic acids and
phospholipids of cell membranes
Phosphorous
minerals that are minimally required by microbes, and
are also essential in enzymatic reactions
Trace elements
extremely reactive
Singlet oxygen
highly unstable, steals electron from
neighboring molecules thereby increasing free radicals
Superoxide free radicals:
most reactive form of oxygen
Hydroxyl radical
are essential organic compounds that cannot
be synthesized by an organism thus must be obtained from the
environment.
Organic growth factors
